In light of this thread viewtopic.php?f=8&t=16224 , I wanted to confirm how to best limit a game to 5.1. We’re not setup to handle 7.1, so I think my safest bet is to ensure that nothing gets sent to the additional 7.1 speakers (aka the ‘sides’).

For 3D events, if I don’t want anything to be heard in the ‘sides’, is my best option to turn down those channels in their corresponding category folder? I’m currently doing a slight volume reduction on the ‘rears’ for all 3D sounds, so it’s not too much more work on the programmer’s end to let me do that. Is there another way to handle this?

As for 2D events, this is more straight forward. I’ll just use the "Speaker level" effect, or the "2D Speaker" settings in the event’s property panel.

Firelight will have to chime in on whether it’s possible to limit the Designer engine to to produce a maximum of 5.1 output on all 7.1 capable devices. I think we did this with our last PS3 title. This, of course, would guarantee that you would not produce any unwanted channel output.

FWIW – From Sound designer standpoint – there are some things to consider in regards to staying in 7.1. Like:
1. You don’t [i:g525z7hs]need[/i:g525z7hs] a 7.1 speaker environment to test and develop a 7.1 game (although at some point you’re gonna want to give it a real listen). If you have set up your 5.1 speaker configuration appropriately (in Windows or on your receiver) the game should down mix to match your set up thus allowing you to hear "virtual back speakers".
2. 7.1 doesn’t cost any more CPU than 5.1 so it’s basically free.
3. 7.1 folds down nicely to 5.1. By summing the rears and the sides with zero reduction of either pair, your 5.1 mix will be virtually identical to the one you would have created in pure 5.1. This fold down technique is specified by both Microsoft (XB1 whitepaper) and Dolby.

And, once Firelight is done swapping the PS3/PS4 sides/rears in Designer [url:g525z7hs]http://www.fmod.org/forum/viewtopic.php?f=8&t=14403#p58278[/url:g525z7hs] you’ll need to remember that the SIDE channels will become synonymous with Dolby’s ‘SURROUND’ channels – which are exactly what you DO want to be sending to when you are developing in 5.1 on the PS3/PS4/XB1.

I am [i:g525z7hs]not[/i:g525z7hs] a big fan of 7.1 and I would not be asking my team to pursue it unless it was little to zero overhead from a both a creative and a technical perspective.

For 3d sounds it is quite trivial, you can use System::set3DSpeakerPosition and set active = false for the sides, using the runtime API.

Because 7.1 is 8 channels to process for the mixer and for the effects, the cost is actually not free, it is 33% higher for 7.1 , but this is not relevant to decoding compressed vorbis voices for example, which may be more significant than mixing and effects, but that depends on your bus set up and use of effects.

Note that the swap option is just that, an option, so if you’re authoring for 5.1 then stick with using the backs in designer, leave the sides alone, and don’t use the new flag, and it will be the same output on all devices.

Thanks, RCarle and Brett! I’ll probably opt to deactivate the sides. This is mostly because I don’t have access to a 7.1 system and I don’t expect I’ll have time to revise my existing 2D sounds to be balanced in 7.1. There are some other reasons why I’m shying away from supporting 7.1, even though I could do a rough’ish mix. In case you’re curious, they are as follows:

Since the game I’m currently working on has a side-scrolling perspective, I find that the rears can often be too loud for 3D sounds (as they get horizontally further away from the listener). To counteract this, with the help of our audio programmer, I’m turning down the rear channels on all 3D sounds and also offsetting the listener position. My concern with allowing 7.1, and not being able to test it too thoroughly, is that I won’t notice sounds that are too loud in the sides. Since the fold-down to 5.1 reduces the sides by X dB and then sends them to the fronts and rears, I’m concerned that the fold-down may mask imbalances in the side channels. I can’t recall what the exact fold-down rules are, but if the fronts and rears get a near-equal amount of the sides, then I might miss an overly loud side if I’m not testing much on a 7.1. This assumes I won’t get any/much time on a 7.1 system.

I’m also concerned about phasing between the sides and rears, and between the sides and fronts with regards to 2D sounds. I do things to protect against phasing between the rears and fronts (that I could also do for the sides), but I’d prefer to verify that all is well in the sides. Without regular access to a 7.1 system, I won’t be able to check that. Plus, my solution to such phasing often involves adding an additional layer and, therefore, adding another voice/stream, and I’m not sure our game can handle many more streams.